The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
An aircraft is moved by several turbojet engines each housed in a nacelle also housing a set of related actuating devices connected to its operation and performing various functions when the turbojet engine is running or stopped. These related actuating devices in particular comprise a mechanical thrust reverser actuating system.
A nacelle generally has a tubular structure along a longitudinal axis comprising an air inlet upstream from the turbojet engine, a midsection intended to surround a fan of the turbojet engine, and a downstream section housing the thrust reverser means and intended to surround the combustion chamber of the turbojet engine. The tubular structure generally ends with a jet nozzle, the outlet of which is situated downstream from the turbojet engine.
Modern nacelles are intended to house a bypass turbojet engine capable of generating, by means of the rotating fan blades, a hot air flow (also called “primary flow”) coming from the combustion chamber of the turbojet engine, and a cold air flow (“secondary flow”), that circulates outside the turbojet engine through an annular passage, also called “annular flow path”.
The term “downstream” here refers to the direction corresponding to the direction of the cold air flow penetrating the turbojet engine. The term “upstream” designates the opposite direction.
The annular flow path is formed in a downstream section by an outer structure, called outer fixed structure (OFS), and a concentric inner structure, called inner fixed structure (IFS), surrounding the structure of the engine strictly speaking downstream from the fan. The inner and outer structures are part of the downstream section. The outer structure may include one or more cowls sliding along the longitudinal axis of the nacelle between a position allowing the reversed airflow to escape and a position preventing such an escape.
A variable-section nozzle at the outlet of the annular flow path is formed by movable elements configured so as to allow a decrease or increase in the discharge section of the air flow at the outlet of the annular flow path so as to optimize the section of the latter based on the flight phase of the aircraft.
However, the devices for actuating said movable elements are cumbersome and make the nacelle heavier.